INFO: task syz.4.221:6908 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.221 state:D stack:25640 pid:6908 tgid:6907 ppid:5602 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x16dc/0x5500 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 jfs_flush_journal+0x719/0xf50 fs/jfs/jfs_logmgr.c:1561 jfs_sync_fs+0x7d/0xa0 fs/jfs/super.c:650 sync_filesystem+0x1ce/0x250 fs/sync.c:66 jfs_reconfigure+0xc6/0x990 fs/jfs/super.c:370 reconfigure_super+0x232/0x8f0 fs/super.c:1020 vfs_cmd_reconfigure fs/fsopen.c:268 [inline] vfs_fsconfig_locked+0x171/0x320 fs/fsopen.c:297 __do_sys_fsconfig fs/fsopen.c:463 [inline] __se_sys_fsconfig+0x6bf/0x810 fs/fsopen.c:350 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f436f38de59 RSP: 002b:00007f436d5e6028 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f436f615fa0 RCX: 00007f436f38de59 RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000004 RBP: 00007f436f423e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f436f616038 R14: 00007f436f615fa0 R15: 00007fffd0031f38 Showing all locks held in the system: 3 locks held by rcuc/0/20: 1 lock held by khungtaskd/38: #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:840 [inline] #0: ffffffff8e1c3000 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5351: #0: ffff8880360b40a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cc62e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x460/0x1360 drivers/tty/n_tty.c:2211 9 locks held by syz-executor/5597: 2 locks held by syz-executor/5607: 2 locks held by syz.4.221/6908: #0: ffff8880321a2460 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:461 [inline] #0: ffff8880321a2460 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x693/0x810 fs/fsopen.c:350 #1: ffff88806181e0d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: vfs_cmd_reconfigure fs/fsopen.c:267 [inline] #1: ffff88806181e0d0 (&type->s_umount_key#61){+.+.}-{4:4}, at: vfs_fsconfig_locked+0x169/0x320 fs/fsopen.c:297 5 locks held by syz.1.727/8646: 3 locks held by syz.5.726/8650: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x17a/0x380 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd7/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 41 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:check_preemption_disabled+0x22/0xe0 lib/smp_processor_id.c:53 Code: 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 d7 cd 5b 07 65 8b 0d cc cd 5b 07 f7 c1 ff ff ff 7f 74 0c 5b 41 5e 41 5f 5d cc cc cc cc cc 9c 59 f7 c1 00 02 00 00 74 ea 65 4c 8b 3d 7e cd RSP: 0018:ffffc90000b27870 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8d89ab86 RDI: ffffffff8bca5f80 RBP: ffffc90000b27a40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8e1c3000 R12: ffff88805ece1790 R13: ffffffff8b08145d R14: ffffffff8e1c3000 R15: ffff88801f6a5d00 FS: 0000000000000000(0000) GS:ffff888125c4d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9f396619bc CR3: 0000000043c84000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_release+0xa1/0x3c0 kernel/locking/lockdep.c:5888 rcu_lock_release include/linux/rcupdate.h:310 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:801 [inline] batadv_iv_ogm_schedule_buff net/batman-adv/bat_iv_ogm.c:862 [inline] batadv_iv_ogm_schedule+0x712/0xfa0 net/batman-adv/bat_iv_ogm.c:918 batadv_iv_send_outstanding_bat_ogm_packet+0x67a/0x790 net/batman-adv/bat_iv_ogm.c:1807 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245